Predicting variation in plant functional traits related to anti-herbivore defences remains a major challenge in ecological research, considering that multiple traits have evolved in response to both abiotic and biotic conditions. Therefore, understanding variation in plant anti-herbivore defence traits requires studying their expression along steep environmental gradients, such as along elevation, where multiple biotic and abiotic factors co-vary. We expand on plant defence theory and propose a novel conceptual framework to address the sources of variations of plant resistance traits at the community level...

In the present paper, Mössbauer spectroscopic studies of dry biomass samples of the cyanobacterium Arthrospira platensis (formerly known as Spirulina platensis) were performed with regard to metabolic iron accumulation. 57 Fe Mössbauer parameters of iron in the biomass correspond to ferrihydrite. Spectra of iron hydroxides in A. platensis biomass differ from those of iron complexes with ethylenediaminetetraacetic acid injected to Zarrouk culture medium. The limit of saturation of A. platensis trichomes with iron in the form of ferrihydrite was found to be 5 μg/ml (0...

Atmospheric temperature increases along with increasing atmospheric CO2 concentration. This is a major concern for agroecosystems. Although the impact of an elevated temperature or increased CO2 has been widely reported, there are few studies investigating the combined effect of these two environmental factors on plant-insect interactions. In this study, plant responses (phenological traits, defensive enzyme activity, secondary compounds, defense-related gene expression and phytohormone) of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae) -susceptible and resistant rice under various conditions (environment, soil type, variety, C...

Xanthohumol (XN) and demethylxanthohumol (DMX) are specialized prenylated chalconoids with multiple pharmaceutical applications that accumulate to high levels in the glandular trichomes of hops ( Humulus lupulus L.). Although all structural enzymes in the XN pathway have been functionally identified, biochemical mechanisms underlying highly efficient production of XN have not been fully resolved. In this study, we characterized two noncatalytic chalcone isomerase (CHI)-like proteins (designated as HlCHIL1 and HlCHIL2) using engineered yeast harboring all genes required for DMX production...

Low-temperature plasma (LTP) is capable of ionizing a broad range of organic molecules at ambient conditions. The coupling of LTP to a mass analyzer delivers chemical profiles from delicate objects. To investigate the suitability of LTP ionization for mass spectrometry (MS) based in vivo studies, we monitored the auxin-regulated nicotine biosynthesis in tobacco (Nicotiana tabacum) and evaluated possible biological effects. The measured nicotine concentrations in different experiments were comparable to literature data obtained with conventional methods...

Morphological transformations in primitive organisms have long been observed; however, its biomechanical roles are largely unexplored. In this study, we investigate the structural advantages of dimorphism in Arthrospira platensis, a filamentous multicellular cyanobacterium. We report that helical trichomes, the default shape, have a higher persistence length (Lp), indicating a higher resistance to bending or a large value of flexural rigidity (kf), the product of the local cell stiffness (E) and the moment of inertia of the trichomes' cross-section (I)...

Many aromatic plants accumulate mixtures of secondary (or specialized) metabolites in anatomical structures called glandular trichomes (GTs). Different GT types may also synthesize different mixtures of secreted metabolites, and this contributes to the enormous chemical diversity reported to occur across species. Over the past two decades, significant progress has been made in characterizing the genes and enzymes that are responsible for the unique metabolic capabilities of GTs in different lineages of flowering plants...

Endopolyploidy occurs when DNA replication takes place without subsequent mitotic nuclear division, resulting in cell-specific ploidy levels within tissues. In plants, endopolyploidy plays an important role in sustaining growth and development, but only a few studies have demonstrated a role in abiotic stress response. In this study, we investigated the function of ploidy level and nuclear and cell size in leaf expansion throughout development and tracked cell-type specific ploidy in the halophyte Mesembryanthemum crystallinum...

Convergent phenotypic evolution is often caused by recurrent changes at particular nodes in the underlying gene regulatory networks (GRNs). The genes at such evolutionary 'hotspots' are thought to maximally affect the phenotype with minimal pleiotropic consequences. This has led to the suggestion that if a GRN is understood in sufficient detail, the path of evolution may be predictable. The repeated evolutionary loss of larval trichomes among Drosophila species is caused by the loss of shavenbaby (svb) expression...

The epitranscriptomic mark N6-methyladenosine (m6A) can be written, read, and erased via the action of a complex network of proteins. m6A-binding proteins read m6A marks and transduce their downstream regulatory effects by altering RNA metabolic processes. The characterization of m6A readers is an essential prerequisite for understanding the roles of m6A in plants, but the identities of m6A readers have been unclear. Here, we characterized the YTH-domain family protein ECT2 as an Arabidopsis thaliana m6A reader whose m6A-binding function is required for normal trichome morphology...

Traffic-generated particulate matter (PM) is a significant fraction of urban PM pollution and little is known about the use of living walls as a short-term strategy to reduce this pollution. The present study evaluated the potential of twenty living wall plants to reduce traffic-based PM using a living wall system located along a busy road in Stoke-on-Trent, UK. An Environmental Scanning Electron Microscope (ESEM) and ImageJ software were employed to quantify PM accumulation on leaves (PM1 , PM2.5 and PM10 ) and their elemental composition was determined using Energy Dispersive X-ray (EDX)...

The main objective of this study was to investigate Artemisia annua plant property variations in terms of plant biomass, glandular trichome numbers, artemisinin production and Guaiacol peroxidase (GPOX) activity when plants are in mutualism with AMF. According to the results, A. annua mutualism with AMF significantly increased the most important and pharmaceutically relevant factors of fresh and dry plant biomass. This increase, especially in the biomass of plant herba (leaves), was 30% higher during the vegetation period and remained high (29% higher than for control) when plants were harvested at the end of the vegetation period...

BACKGROUND: In areas of high exposure to grass pollen, allergic patients are frequently sensitized to profilin, and some develop severe profilin-mediated food reactions. This specific population of patients is ideal to study the relationship between respiratory and food allergies. OBJECTIVE: To determine the role of oral mucosa epithelial barrier integrity in profilin-mediated allergic reactions. METHODS: 38 profilin-allergic patients, stratified into mild or severe according to their clinical history and response to profilin challenge test, together with 6 non-allergic subjects were recruited...

We report for the first time the presence of cluster crystals of calcium oxalate within the glandular trichomes and oil bodies in the mesophyll for Baccharis species. Moreover, the comparative leaf anatomy and micro-morphology of six species of Baccharis, namely B. illinita, B. microdonta, B. pauciflosculosa, B. punctulata, B. reticularioides, and B. sphenophylla is investigated by light and scanning electron microscopy. The studied species exhibited differences in their leaf anatomical features such as the morphology of the cuticle, type and occurrence of the stomata, presence or absence of glandular trichomes, shape of the flagelliform trichomes, and the arrangement of the mesophyll tissues...

The climate change scenarios besides foreseeing a severe drought imposition also emphasize the temperature rising in the Mediterranean region, with special prominence at nighttime. Despite the high olive tree tolerance to severe environmental conditions, stomatal nighttime water loss can change plant water relations, and the related consequences and opportunities, especially under water scarcity, must be clarified. A set of 3-year-old potted olive trees were subjected to three cycles of drought, imposed by withholding irrigation, while another group were continuously irrigated...

PREMISE OF THE STUDY: Leaf surface traits, such as trichome density and wax production, mediate important ecological processes such as anti-herbivory defense and water-use efficiency. We present a phylogenetic analysis of Asclepias plastomes as a framework for analyzing the evolution of trichome density and presence of epicuticular waxes. METHODS: We produced a maximum-likelihood phylogeny using plastomes of 103 species of Asclepias. We reconstructed ancestral states and used model comparisons in a likelihood framework to analyze character evolution across Asclepias...

Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), is a serious global pest of potato, Solanum tuberosum L. Management of L. decemlineata has relied heavily on insecticides, but repeated evolution of insecticide resistance has motivated the exploration and development of alternative strategies, such as plant resistance. The recent development of two diploid potato families derived from crosses between cultivated and wild potato species (S. chacoense and S. berthaultii) has provided a unique opportunity to reexamine plant traits for resistance breeding...

External and internal features of Elaeagnus umbellata leaves were investigated by optical and electron microscopy. The adaxial (upper) and abaxial (lower) leaf surfaces appeared green and silver in color, respectively. There were peltate trichomes on both the adaxial and abaxial leaf surfaces. The peltate trichomes were 200-300 μm in diameter and shield or umbrella-shaped. They had a central dome and 20-30 radiating rays that were fused to form a circular cap in the center and tapered at the end. The density of peltate trichomes was apparently higher on the abaxial leaf surface than on the adaxial leaf surface...

The CRISPR/Cas9 system has emerged as a powerful tool for targeted genome editing in plants and beyond. Double-strand breaks induced by the Cas9 enzyme are repaired by the cell's own repair machinery either by the non-homologous end joining pathway or by homologous recombination (HR). While the first repair mechanism results in random mutations at the double-strand break site, HR uses the genetic information from a highly homologous repair template as blueprint for repair of the break. By offering an artificial repair template, this pathway can be exploited to introduce specific changes at a site of choice in the genome...

Gerbera hieracioides (Kunth) Zardini of the Gerbera -complex (Mutisieae, Asteraceae/Compositae) is distributed in Ecuador and Peru. This perennial herb was first named as Onoseris hieracioides Kunth and was later recognised as Trichocline hieracioides (Kunth) Ferreyra. Now it is generally treated as Gerbera hieracioides (Kunth) Zardini but it has never been included in any section of Gerbera . In this study, the position of Gerbera hieracioides is assessed based on morphology and a molecular phylogeny that includes G...